Here is a simple and powerful LED based night lamp circuit that can be operated directly from the 230V mains supply. The are total 24 white LEDs used and the lamp produces an output of around 15W.The resistance R1 and capacitor C1 provides necessary current limiting. The circuit is sufficiently immune against voltage spikes and surges.

Hi Jay may be your capacitor is faulty. connect 0.25 in series with one pair of LED back to back and with 1k 1 watt also inseries and try for the glow. if nothing happens and if the LEDs glow OK. then the fault is that the LEDs are rated for 3.2volt 15mA.

Hello Seetharaman, I have checked the LEDs with lithium cell. Unfortunately, all 6 LEDs are dead. Yes, I have actually used two capacitors (0.25 & 0.1uF) both at 630v in parallel. I hope that the voltage is not too much if its in parallel? I am not sure if the caps are still working after the test that I have made….Jeh

Hi Jeh one of yur LED might have blown. With a magnifying glass look into LED if any block spot is seen it is blown. you can check each LED’s glow by using a lithium 3 volt disc cell-faster method. Is your 0.35uF rated for 400 volt.

Hello Seetharaman, I was able to assemble the project. Fortunately it was working when I plugged it for 15seconds however, when I switched it off then turned it on after some seconds the LEDs did not glow anymore till now. What do you think is the error? I have used 0.35uF Capacitor and 220ohms 1 watt resistor. There is no sign of burn or any part that gets hot. Thank you, Jeh

Hi Jeh it will be 5mm 3volt @ 20mA variety. So my earlier comment of 8th june is ok for your application. Normally 7.5mm will come as jewel lamp with 2 leads for panel indication use. please donot worry about it. You go ahead thinking as 5mm ( some makes are around 5.5mm with 2 leads one little longer, indicating anode)

Dear Seetharman,I was the one who measured it actually and it is more than 5mm but less than 10mm. The store told me that it is 3volts. It has two leg terminals, cylindrical with almost flat top part. It looks the same as the 3mm size LED. Well, I just dont know if it falls to the 5mm size category. I can send you a photo to your email if you could send me yours.
Thanks, Jeh

Hi Jeh as per the voltage and current requirement of the LEDs the values of C1 and R1 will change. Send me the details of your 7.5mm LED, it is not a standard size. (normally freely available in the market sizes are 3,5,10 mm)

Hi Jeh 3 volt 3mm white LEDs will consume 20mA at 3.6 volts. 3Pairs back to back. Increase C1 to 0.33uF. no other modifications are required. The power consumption will be around 3/4 watts for the modified circuit. By reducing R1 to 220 ohms your consumption will be less than 0.4watts.

Hello Seetharaman,using the same circuit but using only 6pcs 3volts 3mm diameter LEDs, can you help me if what values of capacitor and resistor should I use? I was able to complete the first project but the store run out of LED.

Hi Jeh first LEDs anode to the second LEDs cathode and vice versa first LEDs cathode to second LEDs anode etc. as shown in the above circuit diagram.
with 0.1uF you can connect 1 pair of LEDs back to back and use the illumination will be quite low as only 7mA wll be flowing through the LEDs.
with .033uF a pasir of LEDs will get less than 2.5mA hence you will have only a faint glow.
the charge available in the capacitor is getting completed through the leakage path in your holder circuit and you will have faint glow for a long time. then it will become dark. to avoid this problem add a 100K 1/4 resistance in parallel with C1 which will discharge the capacitor fast hence the glow LEDs will fade away fast.

Thanks Seetharaman for the reply. Just a small clarification, when you say back to back you mean I will connect the two LEDs with one +leg of 1 LED to the -leg of the other LED and vice-versa?
If I would like to use just one 0.1uf cap, how many LEDs and value of resistor should I use? likewise with 0.033uF capacitor?
By the way the circuit is a great one! Congratulations for that! I just dont know if it is normal that when I switch it off some LEDs are a bit glowing and they don’t go off unless I remove totally the unit from the mains…Maybe you could help me again to solve this observations…
Thank you so much, Jeh

Hello Seetharaman, I have 0.1uf/630v and 0.033uf/630v capacitors available in the market. Can you help me if how many LEDs are required for each capacitors? I wanted to increase the nos of LEDs to 50.
Thank you, Jeh

I propose to use about 25 nos white LED in each group amounting to 50 nos. led (3.2v 25mA). I would be using 0.22mfd 400 volts and R1 as 100ohms 1 watt. The Power consumption would be approx. 3.5 watts.

Hi Sison Connect 50LEDs back to back in series as above. Reduce R1 to 220 ohms 1 watt. change C1 to 0.47uF 400Volt. The only drawback is if you view the LEDs directly it will look like they are flashing. but illumination will be ok, you will not notice any flicker.

Hi Ravinder I have assembled with 30 LEDs, it consumes less than 1.5watts, as a night light it is ok. by reducing the resistance to 220ohms 1/4 watt you can further reduce. it was giving low filickering illumination due to each LED operating for half the cycle, as there is no rectifier and filter circuit.

I assembled the above circuit. It is working excellent. I thank CIRCUITS TODAY very much for providing such a circuit. I want to analyze and understand the circuit. I measured the voltage past the capacitor and resister with a digital multimeter but no a.c.voltage is being shown. I connected a zero volt bulb also past the capacitor and Resister in the ciruit but it has not glowed. Why ?Since I am not a technical person, and for the benefit of memebers like me, I want somebody or the Designer to kindly explain how the circuit is working as to:
1) what is the voltage past the capacitor and the resister
2) what is the voltage of the all the LEDs put together
3) what is current in milliamps passing thrugh the LEDs
4) whether the capacitor and resister are considered to be
in series or in parallel, along with the LEDs.
5) why the glowing leds flicker even though it is not highly noticeable. Thanks in advnce. V.Gopalakrishna, Hyderabad, India.